Like in Stalker where the mutant dogs will turn tail and flee if they take too much damage or if you kill enough of their pack members. Red Dead Redemption's animals also ran away if a fight wasn't going their way.
Actually, Rockstar games are pretty good with this sort of stuff in general. I'm pretty sure you could shoot guns of of people's hands in RDR to make them put their hands up, or cause a fatal gunshot wound that would make them crawl around on their belly and call for help. Both GTA 4 and 5's enemies have injury states where they will take potshots at you with a pistol while bleeding on the ground or just passively clutch their wounds until they die.
I guess it wouldn't work in arcadey or linear games where the point is to kill everything on screen, but for anything more open-ended that tries to go for something approaching realism it'd be nice if the enemies you faced felt more alive and/or showed some basic survival instincts.
This is how I've always run my games. I hate the idea of NPCs just being hitpoints and loot. Whenever I set up a combat I'm always thinking about why these people are fighting, what the stakes are, and when they're going to decide they don't want to die and either flee or surrender. Sometimes they might be fighting for something they really believe in, or have their backs up against a wall, and fight to the death. But if it's just random bandits or pirates or something eventually they're going to take their chances fleeing or begging for mercy.
And then the players have to figure out what to do with them, which makes for good RP opportunities and a way for the players to elaborate on who their characters are. I had to tell one of my rogues to stop recruiting every bandit they defeated because her gang was getting too big to keep track of.